$$6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 1

Which of the following statements best describes an isotope?

Accepted Answer

An atom with the same number of protons but a different number of neutrons.

Question 2

A radioactive isotope of carbon, $$^{14}C$$, is used in medical imaging. What makes $$^{14}C$$ radioactive compared to $$^{12}C$$?

Accepted Answer

$$^{14}C$$ has an unstable nucleus due to extra neutrons.

Question 3

Which of the following best explains why noble gases like neon are chemically inert?

Accepted Answer

They have a full valence shell of electrons.

Question 4

What is the atomic number of an atom with 8 protons, 8 neutrons, and 8 electrons?

Accepted Answer

$$8$$

Question 5

Which equation correctly represents the formation of water from its elements?

Accepted Answer

$$2H_2 + O_2$ \rightarrow 2H_2O$$

Question 6

Which of the following is a correct definition of a compound?

Accepted Answer

A substance made of two or more elements in a fixed ratio.

Question 7

A sodium atom ($$Na) $$loses one electron to become a sodium ion ($$Na^+). $$What is the charge of the resulting ion?

Accepted Answer

$$+1$$

Question 8

Which type of chemical bond involves the sharing of electron pairs between atoms?

Accepted Answer

Covalent bond

Question 9

What is the main difference between a polar covalent bond and a nonpolar covalent bond?

Accepted Answer

Polar covalent bonds involve unequal sharing of electrons, while nonpolar covalent bonds involve equal sharing.

Question 10

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom covalently bonded to one electronegative atom and another electronegative atom.

Question 11

Which of the following elements makes up the largest percentage of living matter?

Accepted Answer

Oxygen

Question 12

If an atom has an atomic number of $$6$$ and a mass number of $$14$$, how many neutrons does it have?

Accepted Answer

$$8$$

Question 13

Which of the following best explains the concept of chemical equilibrium?

Accepted Answer

The forward and reverse reactions occur at the same rate, and the concentrations of reactants and products remain constant.

Question 14

Which of the following is a real-world application of radioactive isotopes in medicine?

Accepted Answer

Using radioactive glucose to reveal cancerous tissue in PET scans.

Question 15

Which equation represents the summary reaction for photosynthesis?

Accepted Answer

$$6CO_2 + 6H_2O + 	ext{light energy} ightarrow C_6H_{12}O_6$ + 6O_2$$

Question 16

Which of the following best describes the role of valence electrons in chemical reactivity?

Accepted Answer

Valence electrons determine how atoms interact and bond with other atoms.

Question 17

Which of the following is true about ions?

Accepted Answer

A cation is a positively charged ion, and an anion is a negatively charged ion.

Question 18

Which of the following best explains why molecular shape is important in biology?

Accepted Answer

Molecular shape determines how biological molecules recognize and interact with each other.

Question 19

Which of the following is an example of a redox (oxidation-reduction) reaction in biological systems?

Accepted Answer

The transfer of electrons from glucose to oxygen during cellular respiration.

Question 20

Which of the following statements about van der Waals interactions is correct?

Accepted Answer

They are weak attractions that can become significant when many occur together, such as in a gecko's ability to climb glass.

Chapter 2: The Chemical Context of Life – General Biology Study Notes

Study Guide - Practice Questions